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Synthesis of magnetic bio-nanocomposites for drug release and adsorption applications
, Article South African Journal of Chemical Engineering ; Volume 42 , 2022 , Pages 115-126 ; 10269185 (ISSN) ; Meskini, M ; Qarebaghi, L. M ; Salami, M ; Forouzandehdel, S ; Cheraghali, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Aims: Synthesis of nanocarrier Fe3O4/silica-starch/PNVCL for drug delivery and Fe3O4/GO-starch for antibiotic removal applications Background: In the first part, the new magnetic nanocomposite including Fe3O4 nanoparticles coated with silica, anchored starch nanoparticles, and poly(N-vinylcaprolactam) and then, loaded by acetazolamide. In the second part, magnetic starch nanocomposites were synthesized and modified with graphene oxide. Methods: The drug loading, release and intrinsic cytotoxicity were measured. Also, the potential of Fe3O4/GO-starch as an adsorbent to remove cephalexin antibiotics from aqueous solutions was evaluated. Result: In the first part, the maximum drug adsorption...
Fabrication and evaluation of in vitro studies of biodegradable and antibacterial composite scaffolds based on polylactic acid-polycaprolactone-hydroxyapatite reinforced with graphene and zinc oxide nanoparticles for use in orthopedic surgery
, Article Iranian Journal of Materials Science and Engineering ; Volume 19, Issue 2 , 2022 , Pages 1-19 ; 17350808 (ISSN) ; Saadatabadi, A. R ; Asefnejad, A ; Sharif University of Technology
Iran University of Science and Technology
2022
Abstract
Introduction: Fabrication of fully optimized tissue-engineered materials in order to simulating the natural structure, and enhancing the biological properties of damaged tissue is one of the major challenges in biomedical engineering and regeneration medicine. Although polymeric based membranes have revealed noticeable advancements in bone regeneration, their mechanical stiffens, electrical conductivity and bioactivity need to be tolerated. Methods: Therefore, the present study is designed to generate a multifunctional biomaterial based on polylactic acid (PLA)/ polycaprolactone (PCL)/hydroxyapatite (HA) nanocomposite containing zinc oxide (ZnO) and Graphene (Gr) nanoparticles employing...
Deposition of Nanostructure Antimony Doped Tin Oxide (ATO) on Glass By Sol-Gel
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
Antimony Doped tin oxide as a conductive film has found a wide range of applications and sol-gel method has so advantageous with respect to another methods for preparing ATO thin films. In this study, ATO thin film has been synthesized using a solution containing metal salts of tin chloride and antimony chloride. The microstructure of the obtained films was studied by applying scanning electron microscopy (SEM) and X-ray diffraction patterns (XRD). In diffraction patterns of the acquired ATO layers which was deposited from a sol containing SnCl4.5H2O and SnCl2.2H2O with Sb concentration of 15%mol and layers which was deposited from a sol containing SnCl4.5H2O with Sb concentration of 15%mol...
Synthesis of ZnO and ZnO-TiO2 Nanocoatings by Sol-Gel Methode and Study in Their Antibacterial and Photocatalyst Properties
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
The goal of this study is synthesis of nanocoating on basis of ZnO by Sol-Gel method and evaluation of their antibacterial and photocatalyst properties changes by different values of TiO2. For this purpose in both method of synthesis contents of TiO2 hase been changed from 0-25 molar percent. Dip coat method has been used for coating from sol with 1.4 mm/s withdrawal speed and 2 minute immersion time. After each step of coating samples has been dried at 150oC for 10 minute and for increasing thickness this process has been repeated 4 times. In first method zinc acetate dihydrate in 0.1 M final concentration and titanium tetraisopropoxide are sol precursors at in situ way of synthesis. In...
Synthesis, Characterization and Catalytic Activity of Vanadium(v) Complex with Tridentate Schiff Base Ligand N´-[1-(2-Hydroxynaphthyl) Methylene]-2-Hydroxy Benzohydrazide
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor) ; Mohammadi Boghaei, Davar (Supervisor)
Abstract
In this project a new dioxovanadium (V) complex of Schiff base ligand N`-[1-(2-hydroxynaphthyl)methylene]-2-hydroxy benzohydrazide was synthesized and fully characterized. This complex is a pentacoordinate one in which the dioxo groups are in cis form. For synthesis of this complex, first, the intermediate compound 2-hydroxy benzohydrazide was synthesized from hydrazine and methyl salicylate and condensed with 2-hydroxynaphthaldehyde to give the Schiff base ligand (H2NBD). Then from reaction of ligand and ammonium vanadate in DMF in 65 ̊C, the NH4[VO2(NBD)] was prepared. This complex was fully characterized by UV, NMR and IR spectroscopies and it’s application as catalyst in sulfoxidation...
Extraction conditions for removal of oxidized sulfur compounds in gas oil
, Article Korean Journal of Chemical Engineering ; Volume 30, Issue 3 , 2013 , Pages 700-705 ; 02561115 (ISSN) ; Safekordi, A. A ; Ghaedian, M ; Shafeghat, A ; Sharif University of Technology
2013
Abstract
An experimental study was conducted to investigate the extraction of oxidized sulfur compounds from gas oil. Solvents used for this purpose included acetone, acetonitrile, methanol and propanol. The effect of solvent concentration, solvent to gas oil ratio, temperature, time and number of stages was studied. To select the best solvent and conditions for extraction, two criteria were considered: high desulfurization and more hydrocarbon recovery. Results showed that extraction time and temperature have no significant effect. Methanol for low ability of extraction of oxidized sulfur compounds and propanol for low hydrocarbon recovery were excluded from further experiments. After the tests, the...
Unprecedented selective oxidation of styrene derivatives using a supported iron oxide nanocatalyst in aqueous medium
, Article Advanced Synthesis and Catalysis ; Volume 354, Issue 9 , 2012 , Pages 1707-1711 ; 16154150 (ISSN) ; Karimi, N ; Saidi, M. R ; Primo, A ; Varma, R. S ; Luque, R ; Sharif University of Technology
2012
Abstract
Iron oxide nanoparticles supported on mesoporous silica-type materials have been successfully utilized in the aqueous selective oxidation of alkenes under mild conditions using hydrogen peroxide as green oxidant. The supported catalyst could be easily recovered after completion of the reaction and reused several times without any loss in activity (no metal leaching observed during the reaction), constituting a facile and straightforward example of aqueous oxidation chemistry promoted by iron-based heterogeneous systems. Copyright
Nano-layered manganese oxides as low-cost, easily synthesized, environmentally friendly and efficient catalysts for epoxidation of olefins
, Article RSC Advances ; Volume 2, Issue 9 , 2012 , Pages 3654-3657 ; 20462069 (ISSN) ; Najafpour, M. M ; Nayeri, S ; Pashaei, B ; Bagherzadeh, M ; Sharif University of Technology
2012
Abstract
Incorporation of calcium(ii), zinc(ii) and aluminium(iii) to manganese oxides greatly improved the activity of manganese oxide towards the epoxidation of olefins in the presence of anhydrous tert-butyl hydroperoxide as an oxidant
Pre-treatment and oxidation behavior of sol-gel Co coating on 430 steel in 750°C air with thermal cycling
, Article Surface and Coatings Technology ; Volume 206, Issue 16 , 2012 , Pages 3495-3500 ; 02578972 (ISSN) ; Askari, M ; Gannon, P ; Sharif University of Technology
2012
Abstract
Research and development efforts continue to improve oxidation resistance and electrical conductivity of solid oxide fuel cell (SOFC) interconnects. This research evaluates the performance of a ferritic stainless steel (AISI 430 - a candidate SOFC interconnect material) with and without a Co coating (via sol-gel dip coating technique) with various pre-treatments, during cyclic oxidation exposures up to 750°C in laboratory air. A pre-treatment exposure of Co coated samples to a 750°C reducing atmosphere (prior to oxidation exposures) led to the formation of an effective Co-based spinel oxide coating that lowers oxidation rates by more than 40 times, and substantially lowers area specific...
Synthesis, characterization and in vitro analysis of superparamagnetic iron oxide nanoparticles for targeted hyperthermia therapy
, Article Chemical Papers ; 2020 ; Dabbagh, A ; Abnisa, F ; Karimian, H ; Abu Kasim, N. H ; Wan Daud, W. M. A ; Sharif University of Technology
Springer
2020
Abstract
Abstract: Superparamagnetic iron oxide nanoparticles (SPIONs) are considered as promising magnetic nanoheating agents for diagnostic as well as therapeutic applications due to their biocompatibility and tunability of magnetic properties. These nanoheating agents are commonly synthesized by coprecipitation of two iron precursors, though applying less amount of these chemicals may minimize the toxicity risks for biomedical purposes. The aim of this study is to address this issue by considering the high oxidation vulnerability of ferrous ions to ferric ions to synthesize SPIONs via a single-iron precursor under four varied oxidative conditions. The obtained results implied that the properties...
Cysteic acid grafted to magnetic graphene oxide as a promising recoverable solid acid catalyst for the synthesis of diverse 4H-chromene
, Article Scientific Reports ; Volume 10, Issue 1 , December , 2020 ; Eslami, M ; Hoda, G ; Sharif University of Technology
Nature Research
2020
Abstract
4H-chromenes play a significant role in natural and pharmacological products. Despite continuous advances in the synthesis methodology of these compounds, there is still a lack of a green and efficient method. In this study, we have designed cysteic acid chemically attached to magnetic graphene oxide (MNPs·GO-CysA) as an efficient and reusable solid acid catalyst to synthesize 4H-chromene skeletons via a one-pot three components reaction of an enolizable compound, malononitrile, an aldehyde or isatin, and a mixture of water–ethanol as a green solvent. This new heterogeneous catalyst provides desired products with a good to excellent yield, short time, and mild condition. This procedure...
Catalytic wet peroxide oxidation of phenol : H2O2 gradual addition study
, Article 2008 AIChE Annual Meeting, AIChE 100, Philadelphia, PA, 16 November 2008 through 21 November 2008 ; November , 2008 ; 9780816910502 (ISBN) ; Ebrahimi, A. A ; Shahalami, S ; Sharif University of Technology
2008
Kinetic parameters estimation of MgO-C refractory by shrinking core model
, Article Journal of Materials Science and Technology ; Volume 22, Issue 6 , 2006 , Pages 826-832 ; 10050302 (ISSN) ; Nemati, Z. A ; Sadrnezhaad, S. K ; Moghimi, Z. A ; Sharif University of Technology
2006
Abstract
Kinetics of oxidation of MgO-C refractories was investigated by shrinking core modeling of the gas-solid reactions taking place during heating the porous materials to the high temperatures. Samples containing 4.5-17 wt pct graphite were isothermally oxidized at 1000-1350°C. Weight loss data was compared with predictions of the model. A mixed 2-stage mechanism comprised of pore diffusion plus boundary layer gas transfer was shown to generally control the oxidation rate. Pore diffusion was however more effective, especially at graphite contents lower than 10 wt pct under forced convection blowing of the air. Model calculations showed that effective gas diffusion coefficients were in the range...
Enhancement of self-powered humidity sensing of graphene oxide–based triboelectric nanogenerators by addition of graphene oxide nanoribbons
, Article Microchimica Acta ; Volume 188, Issue 8 , 2021 ; 00263672 (ISSN) ; Mohammadpour, R ; Asadian, E ; Fardindoost, S ; Sasanpour, P ; Sharif University of Technology
Springer
2021
Abstract
A triboelectric nanogenerator (TENG) electrode sensitive to the adsorption of water molecules has been introduced to create a self-powered humidity sensor. Graphene oxide (GO) nanosheets and graphene oxide nanoribbon (GONR) possessing oxygenated functional groups, as well as high dielectric constants, have been proposed as appropriate candidates for this purpose. GO papers have been fabricated in three forms, i.e. pure GO paper, uniform composites of GONR and GO, and double-layer structures of GONR on top of GO. Results showed that all of the prepared paper-based TENGs revealed excellent performances by maximum output voltage above 300 V. As active humidity sensors, the maximum voltage...
Synthesis, characterization and in vitro analysis of superparamagnetic iron oxide nanoparticles for targeted hyperthermia therapy
, Article Chemical Papers ; Volume 75, Issue 2 , 2021 , Pages 669-679 ; 03666352 (ISSN) ; Dabbagh, A ; Abnisa, F ; Karimian, H ; Abu Kasim, N. H ; Wan Daud, W. M. A ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Abstract: Superparamagnetic iron oxide nanoparticles (SPIONs) are considered as promising magnetic nanoheating agents for diagnostic as well as therapeutic applications due to their biocompatibility and tunability of magnetic properties. These nanoheating agents are commonly synthesized by coprecipitation of two iron precursors, though applying less amount of these chemicals may minimize the toxicity risks for biomedical purposes. The aim of this study is to address this issue by considering the high oxidation vulnerability of ferrous ions to ferric ions to synthesize SPIONs via a single-iron precursor under four varied oxidative conditions. The obtained results implied that the properties...
Studies on recycling of zinc-containing waste
, Article REWAS'04 - Global Symposium on Recycling, Waste Treatment and Clean Technology, Madrid, 26 September 2004 through 29 September 2004 ; 2005 , Pages 2797-2799 ; 8495520060 (ISBN) ; Halali, M ; Sharif University of Technology
2005
Abstract
In this report, the possibility of recovering zinc oxide from zinc containing wastes, also the effect of temperature, time and depth of bed on recycling has been studied. Zinc oxide with a purity of 93.5% was obtained
A study of the electro-catalytic oxidation of methanol on a cobalt hydroxide modified glassy carbon electrode
, Article Electrochimica Acta ; Volume 48, Issue 23 , 2003 , Pages 3423-3429 ; 00134686 (ISSN) ; Mahjani, M. G ; Heli, H ; Gobal, F ; Khajehsharifi, H ; Hamedi, M. H ; Sharif University of Technology
2003
Abstract
Cobalt hydroxide modified glassy carbon electrodes (CHM/GC) prepared by the anodic deposition in presence of tartrate ions have been used for the electro-catalytic oxidation of methanol in alkaline solutions where the methods of cyclic voltammetery (CV), chronoamperometry (CA) and impedance spectroscopy (IS) have been employed. In CV studies, in the presence of methanol the peak current of the oxidation of cobalt hydroxide increase is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of methanol is being catalysed through the mediated electron transfer across the cobalt hydroxide layer comprising of cobalt ions of various valence states. A...
The Effect of Metal Oxides on Gasochromic Properties of WO3 Thin Films Formed by Pulsed Laser Deposition
, M.Sc. Thesis Sharif University of Technology ; Mahdavi, Mohammad (Supervisor)
Abstract
Physical and chemical properties of tungsten oxide thin films change reversibly while exposure to hydrogen gas. This property is called gasochromic. To enhance optical properties of such films, nanostructured, amorphous and porous thin films of (WO3)1-x(MeO)x (MeO= TiO2, MoO3, NiO; x=0.09, 0.17, 0.23, 0.29, 0.33) were fabricated by Pulsed Laser Deposition. Molar percentage of Me/W (Me= Ti, Mo and Ni) was changed in films with respect to targets; for Ti and Ni always a reduction, but for Mo an enhancement for low percentages was observed. The reason is the existence of thermal ablation mechanism during deposition, in the other word is different vapor pressure effect. An increment in x for...
Studies on the catalyst preparation methods and kinetic behavior of supported cobalt catalysts for the complete oxidation of cyclohexane
, Article Reaction Kinetics, Mechanisms and Catalysis ; Volume 114, Issue 2 , Jan , 2015 , Pages 611-628 ; 18785190 (ISSN) ; Khorasheh, F ; Shayegan, J ; Sharif University of Technology
Springer Netherlands
2015
Abstract
Low cost dispersed supported cobalt oxide nanocatalysts on activated carbon (AC) were prepared by two different methods: (1) combined impregnation and deposition–precipitation (IMP-DP) and (2) heterogeneous deposition–precipitation (HDP). XRD, TEM, FESEM, BET and Boehm techniques were used for the characterization of the support and the catalysts. Characterization analyses indicated the negative effect of the wet impregnation method on the IMP-DP technique for the preparation of catalysts for the total oxidation of cyclohexane in air. The catalysts prepared by HDP and IMP-DP methods were found to have significant differences in oxidation activity, morphology, particle size, and shape of...
Green and selective oxidation of alcohols by immobilized Pd onto triazole functionalized Fe 3O 4 magnetic nanoparticles
, Article Journal of Chemical Sciences ; 2018 ; 09743626 (ISSN) ; Naimi Jamal, M. R ; Matloubi Moghaddam, F ; Ayati, S. E ; Sharif University of Technology
Abstract
Abstract: Carbonyl compounds were prepared by selective oxidation of alcohols in the presence of recoverable Fe 3O 4@ SiO 2@ Pd magnetic nanocatalyst in aqueous media as a green solvent. Molecular oxygen served as an oxidant. The catalyst was removed from the reaction media by external magnetic field, washed with methanol, and reused for six more times without any considerable reduction in its reactivity. The chemoselectivity and regioselectivity of the catalyst can serve for selective oxidation of primary alcohols in the presence of secondary ones, and for oxidation of unhindered alcohols in the presence of hindered ones. Graphical Abstract: Selective and facile oxidation of alcohols to...